EP 0301917 B1 19980325 - Progressive-multi-focus lens
Title (en)
Progressive-multi-focus lens
Title (de)
Progressive Multifokallinse
Title (fr)
Lentille progressive multifocale
Publication
Application
Priority
JP 19253087 A 19870731
Abstract (en)
[origin: EP0301917A2] A progressive-multi-focus lens (1, 5) for constituting spectacles having long-distance and short-distance focuses, having an area in which the refracting power progressively changes (successively increases) from upper to lower positions generally at the horizontal center of the lens; and a main fixation line (4, 6) generally called an "umbilical meridial" formed in the progressive-change area, in which the degree of astigmatism along the main fixation line is substantially zero, and the main fixation line is gradually displaced toward the nose in accordance with the convergence of the eyes as it extends from an upper position to a lower position. The disposition of the main fixation line displaced toward the nose is varied depending upon the strength of the lens in such a manner that it is shifted upward as the strength of the lens is reduced, thereby optimizing the performance of the lens for a particular user.
IPC 1-7
IPC 8 full level
CPC (source: EP US)
G02C 7/065 (2013.01 - EP US); G02C 2202/12 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0301917 A2 19890201; EP 0301917 A3 19900829; EP 0301917 B1 19980325; DE 3856153 D1 19980430; DE 3856153 T2 19980827; JP 2573956 B2 19970122; JP S6435524 A 19890206; US 4934808 A 19900619
DOCDB simple family (application)
EP 88307089 A 19880801; DE 3856153 T 19880801; JP 19253087 A 19870731; US 22641088 A 19880729